1. Field of the Invention
The present invention concerns a local area network facsimile device having the capability to send and receive electronic mail (email) via a local area network (LAN) or the internet as well as the capability to send and receive facsimile data via a public network as part of the facsimile transmission process.
2. Description of the Conventional Art
A conventional network facsimile device, also known as a network fax, connects to the internet and is communications capable. In addition to having the capability to transmit facsimiles via a public network as part of the facsimile transmission process, such a network facsimile device also has an address conversion table, in which sub-address data received through the facsimile transmission process and network addresses that correspond to the sub-address data are matched and stored. Accordingly, the network facsimile device can take image data received via the public network and transmit, via a LAN, to a communications terminal of the network address corresponding to the sub-address data sent to the network facsimile device from the sender's communications terminal at the time the image data was transmitted. Additionally, if the LAN that is connected to the network facsimile device is further connected to the internet, then the aforementioned network facsimile device can send and receive image data and email to and from other communications terminals connected to a different LAN, via the LAN, internet or intranet, as the case may be.
For example, if the type of transmission used in the aforementioned network facsimile device is the so-called store and forward type, then transmission data from the sender's network facsimile device is temporarily stored in the buffer memory of a mail server such as a Simple Mail Transfer Protocol (SMTP) server where an error check is performed, after which the transmission data is forwarded onward.
As electronic mail reception protocols, there exist that protocol in which email is received directly from the aforementioned SMTP server as well as the so-called Post Office Protocol, or POP, in which email is periodically retrieved from a POP server. When using POP as the email reception protocol, the email address is registered in the facsimile terminal. From among the mail delivered to the aforementioned mail server a user then receives that which matches the user's own email address.
By contrast, a facsimile terminal that uses SMTP as the mail reception protocol, although there is a possibility that email other than that having the email address that is registered in the facsimile terminal may be sent thereto, reception of email other than that of the terminal setting email is restricted.
It should be noted that Japanese Laid-Open Patent Application No. 11-41275, Japanese Laid-Open Patent Application No. 11-234328 and Japanese Laid-Open Patent Application No. 11-261628 teach that which is related to the above-described types of devices.
Thus, for example, Japanese Laid-Open Patent Application No. 11-41275 discloses a method in which, of the registered addresses used to send and receive email, those that are unneeded are automatically deleted. Similarly, Japanese Laid-Open Patent Application No. 11-234328 discloses a method for sending and receiving email when connected to a mail server or accessing a home page. Likewise, Japanese Laid-Open Patent Application No. 11-261628 discloses a method for confirming that email has been sent after sending or receiving email via SMTP.
However, the above-described conventional art entails a drawback. Specifically, when receiving electronic mail using SMTP, it is not possible to register a plurality of email addresses in the network facsimile device's own domain. As a result, even when a plurality of users use the same network facsimile device, that network facsimile device is unable to receive email having an address different from the one email address for that device, which is inconvenient.